Two classes of polymeric electrolytes will be studied by nuclear magnetic resonance (NMR) techniques in conjunction with electrical measurement performed by collaborators elsewhere. The first category concerns electrolytes that are envisioned for utilization in high energy density rechargeable lithium batteries (in particular, for electric vehicle applications). These electrolytes consist of a lithium salt (e.g. LiAsF) dissolved in a mixture of ethylene carbonate and propylene carbonate and immobilized in a polyacrylonitrile matrix. By utilizing variable temperature 7Li linewidth and spin-lattice relaxation in concert with collaborative ionic conductivity measurements, it is hoped that a microscopic description of the Li+ ion transport mechanism will be developed. The second class of materials are commercial perfluorosulfonic acid ion exchange membranes that are key elements in future hydrogen/oxygen fuel cells. The principal goal of the investigation is to obtain a detail understanding of the relationship between water molecular motion and proton transport in the membranes by utilizing deuteron and oxygen-17 NMR measurement of films containing isotopically enriched water, as function of temperature, pressure, and water content. Again, collaborative electrical measurement will be involved. The issues addressed in this proposal are directly related to energy and environment, and thus can be considered to have a major potential impact on human health. Also state-of-the-art NMR techniques employed here could have some relevance to MRI research. However, the main motivation is to steer minority students into the severely under-represented fields of physics and material science.